1. Field of the Invention
The present invention relates to an information processing apparatus, a control method, and a recording medium and, more particularly, to an information processing apparatus capable of switching processing for a print job of an image forming apparatus.
2. Description of the Related Art
An operating system (OS) installed in a host computer is generally provided with a printing system to support printing in an environment where a printer is connected to the host computer that outputs a print request. One known printing system is a CUPS® (Common UNIX Printing System) printing system that runs on Mac OS® X of Apple Computer in the U.S.A. The CUPS printing system is roughly divided into a scheduler, a filter, and a backend. The scheduler mainly manages print jobs. The filter mainly converts image data into data interpretable by a printer. A preprocessing unit called a prefilter can correct image data. More specifically, the preprocessing unit can perform automatic photo correction, noise removal of digital camera images, and the like. The backend mainly sends data interpretable by a printer to the printer.
When connecting a printer to a host computer on an OS or a printing system, the printer can be used with various connection interfaces (connection I/Fs). Examples are USB (Universal Serial Bus) connection, connection (to be referred to as a network connection hereinafter) by network communication using TCP/IP (Transmission Control Protocol/Internet Protocol) or the like, and Bluetooth® connection. LPR (Line PRinter daemon protocol), IPP (Internet Printing Protocol), and the like are widely used as the communication protocol to perform printing using network connection and supported by various OSes. Some printer vendors implement printing by network connection using communication protocols unique to the vendors. In recent years, to enable printing by network connection from various hosts, the number of printers supporting the plurality of communication protocols is growing.
To make a printer usable on a host computer, generally, a printer driver is installed, and the printer is registered in the host computer. When the printer is registered, a print queue for sequentially processing print jobs using the printer driver is generated on the host computer. The print queue changes between the above-described connection I/Fs or communication protocols. A plurality of print queues can be generated for the same printer.
A technique of determining which connection I/F and communication protocol should be used to establish connection from a host computer to a printer is described in, for example, Japanese Patent Laid-Open No. 2004-280572. In Japanese Patent Laid-Open No. 2004-280572, if a plurality of connection paths exist for a network supporting printer having a plurality of connection interface unit connected to a network, the fastest connection I/F and communication protocol are selected.
There exist connection I/Fs and communication protocols which support so-called bidirectional communication so as to not only write data in a printer but also acquire information from the printer and those which can only write data in a printer but cannot acquire information from the printer.
If a printer supports a plurality of connection I/Fs and communication protocols, the host computer detects printers for all connection I/Fs and communication protocols it supports. At the time of printer registration, the operator selects a printer to be registered in the host computer from the displayed printer list to generate a print queue.
For example, assume that a printer supports both a communication protocol A of OS standard and a communication protocol B unique to the printer vendor as the communication protocol of the network I/F. If the operator is going to register the printer connected to a network, both the printer using the communication protocol A and that using the communication protocol B are displayed in the registrable printer list. In this case, the operator may be unable to determine which communication protocol should be used to generate a print queue. Alternatively, the OS may display the registrable printer list that only includes the printer using the communication protocol A of OS standard by default, and the printer using the communication protocol B unique to the printer vendor may be excluded from the default list. In that case, the print queue using the communication protocol unique to the printer vendor is hard to generate.
If a print queue using a communication protocol incapable of bidirectional communication is generated in accordance with the selection of the operator, the print queue cannot provide a printer driver function that needs bidirectional communication.
For example, since the printer driver and the printing system cannot acquire the remaining ink amount information of the printer main body, information of the remaining ink amount or ink running out cannot be displayed on the host computer to notify the operator of it. In addition, when paper has run out during printing, the paper-out error cannot be displayed on the host computer to notify the operator of it.
When printing a CD label or the like, the operator needs to, for example, insert the CD tray at an appropriate timing. Hence, the printer driver displays an operation instruction corresponding to each state on the host computer while monitoring the change in the printer state using bidirectional communication.
However, if bidirectional communication is impossible, the printer driver cannot detect the change in the printer state and therefore cannot display an operation instruction corresponding to current printer information on the display unit of the host computer. For this reason, the operator cannot know the appropriate timing to set the tray with the CD placed thereon. As described above, the print queue incapable of bidirectional communication lowers the operability because the printer state cannot be acquired.